1. Field of the Invention
The invention relates to a joint connector including sub-housings arranged in a plurality of levels.
2. Description of the Related Art
Japanese Patent No. 3433797 relates to a joint connector including sub-housings arranged in a plurality of levels. The joint connector is constructed such that contacts and engaging portions are provided on side surfaces in the respective levels and are brought into contact with each other at proper assembled positions to assemble a plurality of sub-housings in alignment when the respective sub-housings are properly built up.
To reduce mold costs, the above-described joint connector uses common sub-housings formed with a plurality of contact portions and engaging portions on side surfaces. The contact portions and the engaging portions are cut off selectively according to the levels of the sub-housings in the process of building up the sub-housings.
However, the sub-housings built up in a plurality of levels is fit into a mating housing that has a fixed size. The inner walls of cavities for accommodating terminal fittings are thinned if the contact portions and the engaging portions are provided on the side surfaces of the sub-housings, and hence the connector has a reduced strength. There is also an increased burden on an operator due to the need to cut off the contact portions and the engaging portions and to dispose of the sub-housing if the contact portions and the engaging portions are cut off at wrong positions.
Thought has been given to forming retainer insertion openings in mating surfaces of the sub-housings and communicating with the cavities. Retainers could be inserted in the retainer insertion openings and could enter the cavities for locking the terminal fittings in the cavities as the sub-housings are built up. Specified clearances would have to be set between the opening edges of the retainer insertion openings and the retainers to reduce connection forces exerted at the time of building up the sub-housings. This construction would permit displacements of the built-up sub-housings along plane surfaces of the mating surfaces within the set ranges of the clearances. For example, a connecting operation could be performed by pushing only a bottommost sub-housing 100, as shown in FIG. 33. In this situation, the respective sub-housings are displaced gradually backward (left in FIG. 33) in a connecting direction from the lower levels towards the upper levels. As a result, the connecting operation could be completed before the uppermost sub-housing 101 reaches a proper connection position. Further, a lock projection 103 of a lock arm 102 on the uppermost housing 101 may not be fit into a lock hole 201, so that locking is not effected.
The sub-housings have cavities for accommodating terminal fittings, and an end of a wiring harness is connected with the terminal fittings. Each sub-housing often is mounted in an inspection apparatus after the terminal fittings are accommodated in the cavities, but before the sub-housings are built up. An electrical connection test for the terminal fittings then is conducted by bringing conducting probes of the inspection apparatus into contact with the terminal fittings. This electrical connection test can determine if the terminal fittings are connected with a correct wiring harness, but cannot determine whether the terminal fittings are accommodated in proper sub-housings. The wiring harness could be laid incorrectly after the sub-housings are built up if the terminal fittings are accommodated in the wrong sub-housings.
The invention was developed in view of the above situation and an object thereof is to facilitate a building-up operation by preventing an erroneous buildup of sub-housings without causing a reduction in strength.